title: Molecular heterogeneity of large-conductance calcium-activated potassium channels in canine intracardiac ganglia.
abstract: Large conductance calcium-activated potassium (BK) channels are widely expressed in the nervous system. We have recently shown that principal neurons from canine intracardiac ganglia (ICG) express a paxilline- and TEA-sensitive BK current, which increases neuronal excitability. In the present work, we further explore the molecular constituents of the BK current in canine ICG. We found that the β1 and β4 regulatory subunits are expressed in ICG. Single channel voltage-dependence at different calcium concentrations suggested that association of the BKα with a particular β subunit was not enough to explain the channel activity in this tissue. Indeed, we detected the presence of several splice variants of the BKα subunit. In conclusion, BK channels in canine ICG may result from the arrangement of different BKα splice variants, plus accessory β subunits. The particular combinations expressed in canine IC neurons likely rule the excitatory role of BK current in this tissue.
authors.affiliation: Cardiovascular Genetics Center; Institut d'Investigació Biomèdica de Girona (IdIBGi); Department of Medical Sciences; School of Medicine; University of Girona (UdG); Girona, Spain.
authors.forename: Elisabet
authors.initials: E
authors.lastname: Selga
authors.forename: Alexandra
authors.initials: A
authors.lastname: Pérez-Serra
authors.forename: Alba
authors.initials: A
authors.lastname: Moreno-Asso
authors.forename: Seth
authors.initials: S
authors.lastname: Anderson
authors.forename: Kristen
authors.initials: K
authors.lastname: Thomas
authors.forename: Mayurika
authors.initials: M
authors.lastname: Desai
authors.forename: Ramon
authors.initials: R
authors.lastname: Brugada
authors.forename: Guillermo J
authors.initials: GJ
authors.lastname: Pérez
authors.forename: Fabiana S
authors.initials: FS
authors.lastname: Scornik
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000378:metabolism; D004285:Dogs; D005724:Ganglia / Q000378:metabolism*; D051036:Large-Conductance Calcium-Activated Potassium Channels / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D009206:Myocardium / Q000166:cytology*; D009474:Neurons / Q000378:metabolism; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism
chemical_list: D051036:Large-Conductance Calcium-Activated Potassium Channels; D021122:Protein Subunits; D002118:Calcium
keywords: BK channels; alternative splicing; autonomic; intracardiac neurons; β subunits